Dr. Joseph Ciacci loves football, but he fears it. He can’t get enough of the game he prevents his son from playing.

He is in the business of repairing brains. He has seen too much to maintain neutrality.

“The more you know about the issue, the more you think about the issue, the less inclined you are to take a chance,” the UCSD neurosurgeon said. “Because you can’t claim ignorance.”

It’s one thing, Ciacci says, to enter a mine field inadvertently, but quite another to do so when you recognize the risks. Ciacci has had an intimate understanding of those risks since 1977, when his own football career ended with a severe spine injury sustained while covering a high school kickoff.

Amid an avalanche of disturbing new data and harrowing case histories, Ciacci is trying to steer his older son toward water polo.

If concerns about the long-term damage football inflicts attained critical mass with Junior Seau’s suicide, medical professionals have long been attuned and apprehensive. A 2009 study published in the Journal of Athletic Training estimated that high school football annually produces as many as 67,000 reported concussions, and at least as many unreported cases.

With more than a thousand former players pursuing head trauma lawsuits against the NFL, with researchers studying links between football and depression, dementia, memory loss and mood swings, with economists anticipating liability and insurance issues that could threaten the game’s basic viability, the parents of young players are advised to do their homework.

If your son wants to play in a mine field, you should advise him to tread carefully.

“I try to inform them and try to help them to make the best decision that they can,” Ciacci said. “I’m not the type of person who tells people, ‘Don’t do it,’ or ‘Definitely do it.’ I do try to educate them. ...

“I’m finding more and more parents are resistant to having their kids play football and open to understanding the risks involved. ... (I’m) not just some crusader who says, ‘This is the devil’s work.’ Not at all. I’m saying it’s dangerous and people should think about it. It makes you sad a little bit, but you can’t bury your head in the sand.”

When interviewed in March, 2011, Ciacci and his ex-wife, Brenda Holtzclaw, were still weighing the risks as their 260-pound son, Joe, was contemplating a football career at Torrey Pines High School. The family discussion continued into the summer before it was resolved, at least temporarily.

“For now, he’s not playing,” Ciacci said. “We’ve held him out and I’m still not sure that that’s the right decision (but) I’ve been encouraged by the trend of people to do that. Professional athletes have gone on the record as saying they wouldn’t have their kids play. ...

“I think (the younger Joe Ciacci) is disappointed, but I think he’s understanding of it and he realizes it’s based on the intent to protect him from harm that isn’t fully recognized right now.”